Colorectal Cancer

The main types of colorectal cancer include:

• Adenocarcinoma: The most common type accounting for over 90% of cases, originating in the glandular cells lining the colon and rectum.
• Carcinoid Tumours: Develop in the hormone-producing cells of the intestine.
• Gastrointestinal Stromal Tumours (GIST): Rare tumours originating in the connective tissues.
• Lymphomas and Sarcomas: Rare types of colorectal cancers that arise in the lymphatic or connective tissues.

In the early stages, symptoms may be mild or absent. As the disease progresses, the following symptoms can appear:

• Changes in bowel habits (diarrhoea, constipation, or stool narrowing)
• Blood in the stool or rectal bleeding
• Abdominal pain or cramping
• Unexplained weight loss
• Fatigue and weakness
• Persistent feeling of incomplete bowel evacuation

Colorectal cancer develops due to genetic mutations in the cells (changes in the DNA of cells) of the colon or rectum, leading to uncontrolled growth and tumour formation. Several lifestyle, medical, and genetic factors increase the risk:

• Lifestyle-related:
  • Consumption of diets high in red and processed meats
  • Sedentary lifestyle and obesity
  • Smoking
  • Excessive alcohol consumption
• Medical Conditions:
  • Family history of colorectal cancer or inherited syndromes (e.g., Lynch syndrome)
  • History of polyps or inflammatory bowel disease (Crohn’s disease, ulcerative colitis)
  • Type 2 diabetes
• Age and Genetics:
  • Increased risk after 50 years of age
  • Mutations in genes such as APC, KRAS, and TP53.

Colorectal cancer is often diagnosed via a combination of the following techniques:

• Screening Tests:
  • Colonoscopy: A flexible camera tube used to view the inside of the colon; the gold standard for detecting polyps and tumours.
  • Faecal occult blood test (FOBT) or faecal immunochemical test (FIT): Detects hidden blood in stool.
• Imaging Studies:
  • CT colonography (virtual colonoscopy).
  • MRI and CT scans for staging and detecting metastases.
• Biopsy: Tissue samples taken during colonoscopy to confirm cancer diagnosis.
• Blood tests: To evaluate tumour markers such as CEA (carcinoembryonic antigen) to monitor treatment response.
  
  
   

Treatment options depend on the stage, location, and patient factors:

• Early-Stage Cancer:
  • Polypectomy: Removal of polyps during a colonoscopy.
  • Endoscopic mucosal resection (EMR): For larger, localised tumours.
• Locally Advanced Cancer:
  • Surgery:
    • Open, Laparoscopic, or Robotic Approaches for tumour removal.
    • Total Mesorectal Excision (TME) for rectal cancer.
  • Neoadjuvant Therapy: Chemotherapy or radiotherapy before surgery to shrink tumours.
• Advanced Cancer:
  • Chemotherapy: Used to shrink tumours or as adjuvant therapy post-surgery.
  • Targeted Therapy: Monoclonal antibodies (e.g., bevacizumab) targeting cancer pathways.
  • Immunotherapy: Boosts the body’s immune system, used in certain patients with high microsatellite instability (MSI-H).
  • Palliative Care: To manage symptoms and improve quality of life in metastatic cases.

• Neo-adjuvant chemo and radiotherapy: Modern radiotherapy techniques have enabled sphincter-preserving surgeries for low rectal tumours, reducing the need for more invasive procedures and permanent stomas (surgically created openings for waste elimination).
• Total mesorectal excision (TME): Introduced by Heald et al., this technique removes the rectum and surrounding tissue along natural planes, ensuring complete removal of vasculo-lymphatic pathways and reducing local recurrence. TME is pivotal for achieving optimal oncological outcomes.
• Complete mesocolic excision (CME) with central vascular ligation (CVL): Adopted by Hohenberger et al., this method for colon cancer removes intact mesocolic tissue and lymph nodes, lowering the risk of systemic disease spread.
• Laparoscopic colorectal surgery (LCS): Minimally invasive laparoscopic techniques (using small cuts and a camera) have evolved significantly, offering comparable long-term outcomes to open surgery for colorectal cancer. Short-term benefits, including faster recovery, reduced pain, and shorter hospital stays, have been well-documented in multiple studies.
• Robotic colorectal surgery (RCS): Robotic surgery addresses many limitations of laparoscopy, such as restricted instrument mobility, tremor amplification, and the absence of 3D vision. With robotic systems like the da Vinci Surgical System, surgeons gain enhanced precision, better ergonomics, and improved control over surgical instruments.

Advantages of Robotic Surgery

• Enhanced precision: Greater manoeuverability with flexible EndoWrist instruments.
• Improved ergonomics: Surgeons experience reduced fatigue and better control.
• Reduced conversion rates from robotic to open surgery: Studies report conversion rates as low as 0–4.9%.
• Positive oncological outcomes: Comparable or superior cancer clearance, low circumferential resection margin (CRM) positivity, and reduced local recurrence rates.

Supporting Evidence for Robotic Surgery

Several studies validate the safety and efficacy of robotic colorectal surgery. For instance:

• Long-term outcomes demonstrate three-year disease-free survival rates of 73.7% to 79.2% and overall survival rates of 92% to 97%.
• Studies, including hybrid and fully robotic approaches, consistently show promising results for rectal cancer management.

You should consult a doctor if you notice persistent changes in your bowel habits, blood in your stool, unexplained abdominal pain, or unintentional weight loss. Early detection through screening is crucial, especially for people over 50 years or those with a family history of colorectal cancer.

Although not all cases can be prevented, risk can be reduced by:

• Eating a balanced diet rich in fruits, vegetables, and fibre while reducing red and processed meats.
• Exercising regularly and maintaining a healthy weight.
• Avoiding smoking and limiting alcohol consumption.
• Undergoing recommended screening tests (such as colonoscopy) after age 45–50 years, or earlier if you have risk factors.

If colorectal cancer is suspected or confirmed, several specialists may be involved:

• Gastroenterologist: Performs colonoscopies and manages early detection.
• Colorectal surgeon: Performs surgery for tumour removal.
• Oncologist: Provides chemotherapy, targeted therapy, or immunotherapy.

In most cases, care is coordinated by a multidisciplinary team, ensuring a personalised treatment plan for each patient.